Study On Upgrading Coal Slime Of Liu Jiakou Coal Preparation Plant By Flotation

Coal resources reserves is rich in our country, at the low metamorphic stage of low rank coal account for more than 55% of China’s proven coal reserves. With the domestic energy demand growing and high quality coal resources reduce, in the foreseeable future, Comprehensive utilization of low rank coal will be supporting the potential of future energy needs. The slime of low rank coal is hard to float because of the large amount of oxygen functional groups and poor surface hydrophobicity, and the fine coal slime of difficult processing is one of the important reasons of restricting the economic development of coal enterprises. Upgrading the low rank coal slime can use the technical means of flotation, but because of the conventional flotation is difficult, This paper is used the coal slime of Liu Jiakou as an example, Using the new collector FO and variable diameter combination air flotation column to solve the problem of low rank coal flotation, and discusses the mechanism of the new collector FO improve low rank coal slime flotability. The main research contents are as follows:This paper through the industrial analysis and elemental analysis, infrared spectrum analysis, particle size composition analysis, density analysis and so on, and get the basic properties of the coal slime of Liu Jiakou: there are many alkyl side chain and the content of the aromatic nucleus is less in coal molecular structure, oxygen functional groups are more in coal. Grain composition show that fine grain content is more, so need to select effective separation equipment for the sorting; Density show that the coal slime through sorting is expected to get high rate of qualified that added to gravity fine cleaned coal, achieve the rational use of coal slime. Coal slime contact angle measurement show that the slime contact angle is small, natural flotability is poor, usual flotation need to add a lot of collector that can improve the surface hydrophobicity, The coal slime to obtain economic effective separation need to seek new flotation reagents.In the laboratory do usual flotation experimental study to the coal slime from the Liu Jiakou coal preparation plants by using light diesel oil. The research shows: flotation reagents consumption is high, the cleaned coal yield is low, the concentrate combustible material recovery is low. When the concentration of flotation is 80 g/L, light diesel oil consumption is 3000 g/t, dosage of foaming agent is 600 g/t, flotation clean coal ash is 14.57%, clean coal rate is 60.68%, the tail coal ash is 57.72%, combustible material recovery is 75.72%. The new collector FO flotation experiment research by flotation machine, The research shows: The new collector FO flotation test results is obviously better than the light diesel oil flotation test results. When the concentration of flotation is 80 g/L, dosage of collector is 2500 g/t, dosage of foaming agent is 400 g/t, flotation clean coal ash is 17.42%, clean coal rate is 71.81%, the high calorific value is 5779cal/g,the tail coal ash is 67.07%, combustible material recovery is 86.46%. Using FTIR and XPS analyses the mechanism of the new collector FO, The research shows: The new collector FO contains a certain amount of oxygen-containing groups, the hydroxyl group in new collector FO most likely to be bonding with C- O groups on the surface of the coal slime by hydrogen bonding, so it can improve the flotability of coal slime.Study on the coal slime of the Liu Jiakou coal preparation plants by using the new collector FO and variable diameter combination inflatable flotation column in lab, and good flotation indexes were obtained. When the dosage of the new collector FO is 2500 g/t, dosage of foaming agent is 400 g/t, flotation feeding is 400 ml/min, the middling circulating pressure is 0.20 MPa, microporous ceramic inflation pressure is 0.12 MPa, the concentration of flotation is 80 g/L, can get ash is 17.72%, yield is 74.42%, the high calorific value is 5746cal/g of clean coal, tail coal ash is 69.74%, combustible material recovery is 88.78%.Study on the coal slime of the Liu Jiakou coal preparation plants by using the new collector FO and variable diameter combination inflatable flotation column by semi-industrial test, The research shows: using the new collector FO instead of light diesel oil as collector can obviously reduce the dosage of reagents, when the feeding is 5 m3 / h, the dosage of new collector FO is 2000 g/t, dosage of foaming agent is 600 g/t, the feeding ash is 25.44%, flotation clean coal ash is 14.37%, clean coal rate is 80.03%, the high calorific value is 6131cal/g,the tail coal ash is 69.81%, combustible material recovery is 91.91%.Using the new collector FO and variable diameter combination inflatable flotation column can solve the coal slime which is difficult through flotation and reagent consumption is high of Liu Jiakou coal preparation plant in the lab and semi-industrial test, for the low rank coal slime flotation provides a reliable technical method, it provides a reliable technology for the low rank coal slime flotation.